Manner op constructing- the ordinary thumb-latch for doors



UNITED sTATEs PATENT oEEicE.

, EDMUND PARKER, 0F MERIDEN, CONNECTICUT.

MANNER OF CONSTRUGTINGTHE ORDINARY THUMB-LATCH FOR DOORS.

Specification of Letters Patent No. 2,518, dated March 28, 1842.

To all whom t may concern:

Be it known that I, EDMUND PARKER, of Meriden, in the county of New Haven and State of Connecticut, have invented certain Improvements in Common Thumb-Latches; and I do hereby declare that the following is a full and exact description thereof.

My irst improvement is in the manner in which I form the opening in the upper plate of the handle, through which the shank, or lifting part of the thumb piece, passes, and adapt the said thumb piece thereto; and my second improvement is in the manner of forming the plate and joint pin, which constitutes the fulcrum on which the latch works, so as to simplify its construction,'and

thereby to render said latch at a reduced cost, while it possesses all the desirable properties of such an instrument.

In the accompanying drawing, Figure l, is a front view of the handle of the latch; A, being the upper plate thereof through which the thumb piece is to pass; and Fig. 2, is a side view of the thumb piece, with its shank, or lifter, B, being the thumb piece and C, the shank, or lifter.

a, a, Fig. l, is the part of the opening in the plate A, which is to receive and retain the thumb piece when the latch is affixed to a door; the part b, of the thumb piece then resting on the lower part of the opening a, a, which thus becomes its fulcrum. The descending part, or shoulder, C, of the` thumb piece bears against the back of the plate A, and prevents the thumb piece from moving forward, out of its proper place, while the back portion of the part B, by `its bearing against the face of the plate A, prevents its moving inward. To give room for" the insertion of the shanklof the thumb piece, it is necessary that there be an openl ing in the plate A, equal to the width of the shank from c, to c, and this I obtain by extending the opening in the plate A, obliquely, as from b, to b. In this direction the shank is inserted, and is then rotated so as to occupy the space represented by a, a. The mortise in the door is made to correspond with this space, and when the handle is screwed in place, the thumb piece will be retained in its proper position.

Fig. 3, is the latch, and Fig. 4, is the inner side of a cast metal plate which is to be screwed on to the door, and constitutes the support and fulcrum of the rear end `of the latch. The plate, Fig. 4;, has a pin CZ, cast on it which is to enter the hole d, in the latch, and this plate is to be attached to the door by a single screw, there being small projections, or cheek pins, e, e, cast on it, which prevent its turning around on the screw. At f, f, there is an offset, allowing for the thickness ofthe latch. The other parts of the latch, consisting of the staple and catch, may be constructed in any of the known ways, no further improvement being claimed therein.

What I claim as constituting my improvements in the thumb latch, is, first,

The forming of the opening b', Z9, in the plate A, in a direction standing at an angle with the opening a, a, and of such length as to allow the shank of the thumb piece to pass entirely through it, and in adapting these parts to each other, in the manner set forth, so that by rotating the thumb piece itwill be made to occupy the part a a, of said opening.

EDMUND PARKER. .VVitnesses:

JOHN PARKER, CITAS. PARKER. 

